Methods of making glass bodies by a sol-gel process are known, and some of the methods have facilitated making of glass bodies of substantial size. See, for instance, U.S. Pat. No. 5,379,364, incorporated herein by reference. For instance, the method can be used to make high silica (typically &gt;85 weight % SiO.sub.2) bodies for use in optical fiber manufacture.
It is frequently not easy to remove a gel body from the mold in which it was produced, due to adhesion of the gel to the mold. In case the body has a simple shape (e.g., rod or tube) release can typically be accomplished by pushing the body out of the mold with the aid of a plunger inserted from one end. However, this approach obviously cannot be applied if the mold is not open at both ends, or if the shape is complex. Furthermore, the problem is aggravated by the typically relatively low strength of the wet gel body. Sol-gel methods could be advantageously used in the manufacture of high silica glass bodies of relatively complex shape (e.g., crucibles, rings), if the above referred-to release problem could be overcome. This application discloses a method of making a sol-gel body that overcomes the release problem.